(* ::Package:: *)

 


(* ::Section:: *)
(* ExtraFactor *)


(* ::Text:: *)
(*`ExtraFactor` is an option for `FermionSpinSum`. The setting `ExtraFactor -> fa`  multiplies the whole amplitude with the factor `fa` before squaring.*)


(* ::Subsection:: *)
(* See also *)


(* ::Text:: *)
(*FermionSpinSum.*)


(* ::Subsection:: *)
(* Examples *)
